This invention relates to intercom systems and more particularly to a remote banking system intercom for communication between a bank teller location and a remote customer location.
In the drive-in banking field, a form of remote banking, the bank teller and customer are usually separated by a distance anywhere from 6 to 30 feet, with the customer being in his car and the teller in a fully-enclosed booth attached to the main bank building which has a window looking out on the customer terminal. There may be a single teller station uniquely associated with one customer unit, or alternatively several teller stations servicing an even larger number of customer units, with each teller being able to service any one of the customers. Such drive-in systems, whether multistation or not, permit the customer to conduct banking business from his car. In a related type of remote banking system, a sidewalk window is provided where customers, albeit not in cars, conduct their business from the sidewalk without having to enter the bank.
Remote banking systems of the types described require some method for transferring cash, checks, deposit slips and the like between the teller and the customer. In one form, a sliding drawer, controlled by the teller, is provided. The drawer is opened proximate the customer to permit the customer to deposit a check or cash therein. The teller then closes the drawer and thereafter removes the articles from the drawer. The teller then performs certain operations for accounting purposes before placing a receipt, cash, or the like in the drawer. The drawer is again opened to the customer to allow the customer to remove the item from the drawer. While a sliding drawer is commonly used, a pneumatic carrier conveying system is also used, the pneumatic carrier system taking the place of the sliding drawer. An advantage of the pneumatic carrier approach is that it permits the teller to be located large distances from the customer. Pneumatic systems are particularly adaptable to drive-in or walk-up banking systems having many customer locations serviced by one or more tellers.
In all remote banking systems an intercommunication system is necessary to permit conversation between the teller who is in an enclosed booth, and the customer who may be many feet away. The customer must be able to inform the teller of any special request he may have, for example, the type of change he would prefer, and the teller has to be able to speak to the customer, for example, to ask the customer to endorse a check.
Experience has shown that it is preferable to place the teller in control of the direction of communication for the intercom since it is the teller who most often must initiate conversation. Additionally, for ease of operation the communication system should operate with as little manual intervention as possible to permit the teller and the customer to use their hands for other purposes. Accordingly, by permitting the teller's voice to control the direction of communication, not only will the teller be in control but the teller's hands will be free to write or to use them for some other transaction-related purpose. Thus, the system is arranged such that normally it permits the customer to talk to the teller, but switches automatically when the teller talks to allow him to communicate with the customer.
In a remote banking system ambient noise is customarily present at the teller location. Such noise can be caused by the mechanical movement of the cash drawer and/or pneumatic carriers or originate from some other source of ambient noise at the teller location. If these ambient noises at the teller location occur when the customer is speaking, it is possible, particularly when the ambient noise level is high, that the voice switching circuitry of the system, if it cannot discriminate between teller speech and noise, will switch the direction of communication to the teller speech transmission mode, inadvertently cutting off the customer.
It is the primary object of this invention to provide an intercommunication system for remote banking installations of the type in which only the teller speech controls the direction of communication, which is capable of discriminating between ambient noise and speech occurring at the teller location such that the system switches to the teller speech transmission mode only in response to teller speech, thereby avoiding inadvertent communication direction switching due to ambient noise at the teller location.
This and other objects and advantages of the invention are achieved in a voice-operated bidirectional intercom system by providing a noise microphone at the teller location separate and apart from the teller speech microphone, and control means responsive to the amplified outputs of the noise and teller speech microphones for switching the system to the teller speech transmission mode when the outputs bear a predetermined relation to each other. Specifically, and to preclude such predetermined relation from being created in response to ambient noise, the overall gains of the noise and teller speech microphone channels are selected to cause the locust of points of different sound source positions, whereat equal electrical signal outputs of the noise and teller speech channels are produced by a sound source, to form a closed surface of relatively small diameter which envelopes the teller microphone while excluding from the interior thereof the noise microphone. When the teller speech and noise channel gains are so selected, a noise source lying exteriorly of the predetermined closed surface surrounding the teller microphone cannot cause electrical signal outputs of the noise and teller speech channels to bear the predetermined relationship necessary to switch the system to its teller speech transmission mode. In addition, and providing there is no noise source within the predetermined closed surface, when the teller speech and noise channel gains are selected as indicated, only a source of teller speech located within the predetermined closed surface surrounding the teller microphone can cause the outputs of the noise and teller speech channels to bear the predetermined relation necessary to switch the system to its teller speech transmission mode. Thus, the system discriminates between a source of teller speech located within the closed surface surrounding the teller speech microphone and a noise source located exteriorly thereof even though the intensity of the noise source measured at the teller microphone has a greater intensity than that of the speech source measured at the teller microphone.
In a preferred form of the invention the gains of the noise and teller speech microphone channels are adjusted such that the gain of the noise channel is approximately twice the gain of the teller speech channel, and the noise microphone located approximately eight inches behind the speech microphone, with the result that the region enclosing the teller microphone within which a teller speech source must be located to switch the system to its teller speech transmission mode has a radius of approximately 5 inches. With the region surrounding the teller speech microphone so dimensioned, the probability is small that a noise source would be located within the region, rendering the chances rather remote that the system could be inadvertently switched to its teller speech transmission mode by a noise source located within the active region of the teller microphone.